operator &~=

lexer.c

@@ -834,7 +834,7 @@ static int GMQCC_WARN lex_finish_digit(lex_file *lex, int lastch)
 
 int lex_do(lex_file *lex)
 {
-    int ch, nextch;
+    int ch, nextch, thirdch;
 
     lex_token_new(lex);
 #if 0
@@ -1114,6 +1114,16 @@ int lex_do(lex_file *lex)
             lex_tokench(lex, nextch);
         } else if (ch == '-' && nextch == '>') {
             lex_tokench(lex, nextch);
+        } else if (ch == '&' && nextch == '~') {
+            thirdch = lex_getch(lex);
+            if (thirdch != '=') {
+                lex_ungetch(lex, thirdch);
+                lex_ungetch(lex, nextch);
+            }
+            else {
+                lex_tokench(lex, nextch);
+                lex_tokench(lex, thirdch);
+            }
         } else
             lex_ungetch(lex, nextch);
 

lexer.h

@@ -238,6 +238,7 @@ static const oper_info fte_operators[] = {
     { "%=",  2, opid2('%','='),     ASSOC_RIGHT, 8,  0 },
     { "&=",  2, opid2('&','='),     ASSOC_RIGHT, 8,  0 },
     { "|=",  2, opid2('|','='),     ASSOC_RIGHT, 8,  0 },
+    { "&~=", 2, opid3('&','~','='), ASSOC_RIGHT, 8,  0 },
 
     { "&&",  2, opid2('&','&'),     ASSOC_LEFT,  5,  0 },
     { "||",  2, opid2('|','|'),     ASSOC_LEFT,  5,  0 },

parser.c

@@ -1032,6 +1032,27 @@ static bool parser_sy_pop(parser_t *parser, shunt *sy)
                                                     (op->id == opid2('&','=') ? INSTR_BITAND : INSTR_BITOR),
                                                     exprs[0], exprs[1]);
             break;
+        case opid3('&','~','='):
+            /* This is like: a &= ~(b);
+             * But QC has no bitwise-not, so we implement it as
+             * a -= a & (b);
+             */
+            if (NotSameType(TYPE_FLOAT)) {
+                ast_type_to_string(exprs[0], ty1, sizeof(ty1));
+                ast_type_to_string(exprs[1], ty2, sizeof(ty2));
+                parseerror(parser, "invalid types used in expression: %s and %s",
+                           ty1, ty2);
+                return false;
+            }
+            if (ast_istype(exprs[0], ast_entfield))
+                assignop = type_storep_instr[exprs[0]->expression.vtype];
+            else
+                assignop = type_store_instr[exprs[0]->expression.vtype];
+            out = (ast_expression*)ast_binary_new(ctx, INSTR_BITAND, exprs[0], exprs[1]);
+            if (!out)
+                return false;
+            out = (ast_expression*)ast_binstore_new(ctx, assignop, INSTR_SUB_F, exprs[0], out);
+            break;
     }
 #undef NotSameType
 

tests/operators.qc

@@ -56,4 +56,7 @@ void main() {
 	a = 1;
 	print(ftos(a |= 2), " = 3\n");
 	print(ftos(a &= 6), " = 2\n");
+	a = 7;
+
+	print(ftos(a &~= 3), " = 4\n");
 }

tests/operators.tmpl

@@ -18,3 +18,4 @@ M: '6 8 10' = '6 8 10'
 M: '3 4 5' = '3 4 5'
 M: 3 = 3
 M: 2 = 2
+M: 4 = 4